For me this series is a 8.5/10.

Firstly, seeing Yeo Jin Goo in the cast means, this drama would be worth watching, as he never picks normal scripts, his drama's are always interesting.

Secondly it's my first time watching Shin Ha Kyun, I had no idea who he was, but from the first episode onwards, I am blown away by his acting skills. His acting is phenomenal! Definitely one of the best actors in Korea, and his performance deserves accolades.

Third, it's obviously a thriller, with a plot that spans 21 years back, a small town involved with a lot of central characters, unfortunately for me, a thriller is not a real thriller if the plot is predictable at times. The drama definitely had it's twists but certain key plot points were predictable from very early on, hence the reason why my rating is 8.5 and not higher.

Forth, the strong point of this drama definitely is the unique bromance/relation between Yeo Jin Goo and Shin Ha Kyun's character. This relation is what drives this whole drama and makes this worth watching.

Lastly, the OST! was mind-blowing, kudos to whoever did it, brilliantly placed background music. I usually finish thrillers in 1 or 2 days max, but unfortunately as I found the plot a bit draggy, I took quite a few days of break in-between the episodes.

Definitely worth watching once, for the 2 ML's connection and the superb acting.